The present invention relates to a vane compressor for compressing a gaseous medium such as refrigerant, and more particularly to improvements in or to an oil separator for removing oil contained in the gaseous medium.
A vane compressor is already known e.g., from U.S. Pat. Nos. 2,522,824 and 3,834,846 which is of the type including a rotary shaft arranged to be rotated by an associated prime mover; a rotor secured to said rotary shaft for rotation in unison therewith and having a plurality of slits formed in an outer peripheral surface thereof; a plurality of vanes radially movably inserted in said slits; and a pump housing having its interior formed as an endless cam surface and accommodating said rotor and said vanes, the rotor, the vanes and the pump housing cooperating to define pump working chambers between them; a casing enclosing said pump housing in a fashion defining a discharge pressure chamber between the pump housing and the casing, whereby rotation of the rotor causes a gaseous medium such as refrigerant introduced into the pump working chambers to be pressurized for delivery outside the casing via the discharge pressure chamber.
The gaseous medium contains an oil dispersed therein in the form of fine particles for lubricating the sliding machine parts of the compressor such as bearings. The lubricating oil is discharged from the compressor together with the gaseous medium and is fed to an evaporator and a condenser associated with the compressor. Some of the lubricating oil stays in the evaporator and the condenser, causing a reduction in the heat transfer rate of these units. To prevent this, conventionally an oil separator is provided in the discharge pressure chamber for separating oil from the gaseous medium, storing the separated oil in the lower part of the discharge pressure chamber for recycling of the same to lubricate the sliding machine parts of the compressor.
A conventional typical type of oil separator comprises guide plates mounted on the pump housing for guiding toward the discharge pressure chamber a compressed medium pumped out through pump outlets formed in the cam ring, and a gauze member disposed in the discharge pressure chamber, whereby the compressed medium is decelerated and turned in passing the gauze member to have removed oil dispersed therein. However, such conventional type oil separator does not effectively separate oil from the gaseous medium, particularly when used in an apparatus having a high rotational speed and accordingly a high oil consumption such as a vane compressor.